The one point getting missed here. Cap found Bucky laid out on a lab table. Who is to say he was not the subject of Red Skull's own experiments? And who is to say those experiments didn't allow Bucky to survive that fall if he plunged into a snow drift instead of the side of the mountain? It goes without saying he will become the Winter Soldier in modern times. I feel confident the Red Skull will find him and exploit him.

Funny you should say that, because it's true. On the commentary for the DVD, they talked about Bucky going through a version of the super-soldier process, which makes it so he could survive that fall.